Nicholas Petris, who eloquently championed liberal causes as an East Bay representative in the Legislature for 37 years, died Wednesday at an Oakland nursing center after a two-year bout with Alzheimer's disease, relatives said. He was 90.

The son of Greek immigrants, he advanced ideas that were sometimes so far ahead of their time that staffers referred to the years between proposal and acceptance as the "Petris gap."

"Nick Petris was a hero to me as an elected official and as a Greek American man who set the highest standards," said Art Agnos, who served with Mr. Petris in the Legislature and went on to become San Francisco mayor.

"He had a passion to fight for the needs of the poor, the sick and disabled," Agnos said, "as well as the intellect to anticipate the future."

Mr. Petris was often controversial. In the late 1960s, he introduced a bill calling for the elimination of the internal-combustion engine, causing outrage in the auto industry. The bill eventually failed, but his efforts ushered in an era of clean-fuel regulation and air pollution laws in California that were often stricter than national standards.

The Lanterman-Petris-Short Act, passed in 1967, barred the involuntary commitment of most people with mental health problems. Mr. Petris also wrote laws banning smoking on airplanes, trains and buses, and it was his legislation that required redevelopment agencies to build housing for low-income families.

He graduated from Stanford University Law School in 1949 and worked as a lawyer before being elected to the Assembly in 1959 and the state Senate in 1967.

Known for eloquence

His eloquence was legendary. One speech about how budget cuts would affect the poor and mentally ill was so moving that a prominent Republican legislator told him afterward he regretted having to vote against Mr. Petris' position.

"He was really a giant of the Legislature, a fantastic orator in the Greek tradition who people would just stop and listen to," said former state Sen. John Burton, now the chairman of the California Democratic Party. "I don't think he had a single enemy. If you didn't like Nick Petris, you didn't like vanilla ice cream."

Term limits compelled Mr. Petris to retire in 1996.

Mr. Petris was married for 60 years to the former Anna Vlahos, who died in 2010. He is survived by his brother, Gus Petris of Oakland, his longtime caretaker, Noula Vlahakis of Oakland, and several nieces, nephews, cousins and in-laws.

Funeral services will be held at 11 a.m. Tuesday at the Greek Orthodox Church, 4700 Lincoln Ave. in Oakland.